Last summer, when the bond market was falling, leading to big losses for Pimco, Gross turned more combative than usual, his colleagues tell the Journal. He was openly arguing with El-Erian, which had been a rare occurrence.

In a reorganization last month following El-Erian's departure announcement, Pimco named four deputy chief investment officers.

"Going forward there will be more focus on strategy and markets rather than policy, and these are the people on the front lines of strategy and alpha," Gross told Bloomberg. "You can’t just do what you want, but you will be able to react to markets a little quicker rather than wait for the investment committee to meet at noon."

In a letter posted earlier this month on Pimco's website, Gross said: "We will take turns chairing our daily meetings, which will allow for greater focus on certain sectors and regions. I also find that I often prefer to sit at the side of the table rather than at the head of it. I can contribute more effectively that way, learn more by listening, and it gives others the opportunity to lead."

Pimco observers considered the letter a response to clients who have grown edgy about the unexpected changes and Pimco's recent investment calls, Reuters reported.

"I think Pimco did this because they were caught totally off guard by Mohamed leaving," Morningstar senior research analyst Eric Jacobson told Reuters. "My impression is that they've been getting tremendous blowback from their clients, and now they are responding publicly."